Combined telephone-exchange and fire-alarm system.



No. 647,307. Patented Apr. 10, I900.

J. M. LATIMER. COMB'NED TELEPHQNE EXCHANGE AND FIRE ALARM SYSTHL I i pucmon filed July 3, 1899.) o Model.)

3 Sheets-Sheet Witnesses: I Inventof/ h M L Z arms 52 mar, W 0 n J v b Ln A/[orggy THE uonms PETERS c9, vupmcrmcawmqmgtogg. p. c

No. 647,307. Patented Apr. l0, I900.

J. M. LATIMER.

COMBINED TELEPHONE EXCHANGE AND FIRE ALARM SYSTEM.

' (Application filed July 3, 1899.) (No M01101.) 3 ShaatsSheet 2.

Witne s 5 e s Inventor,

John Morrzs L a/Jmsr,

WW6 7 0mm M?? ,AHUilggL No. 647,307. Patented Apr. l0, I900.

J. MQLATIMER- COMBINED TE LE PHONE EXCHANGE AND FIRE ALARM SYSTEM.

(Application filed July 3, 1899.) (No Model.)

3 Sheets-Sheet 3.

Wi tne s s e s= Q Inventor,

- b M I" Lafimer", Wa M /0 n or 15 M if 94W I Affor n gc JOHN MORRIS LATIMER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE UNITED PNEUMATIC FIRE ALARM TELEGRAPH COMPANY, OF NEIV JERSEY.

COMBINED TELEPHONE-EXCHANGE AND FIRE-ALARM SYSTEM.

SPECIFICATION forming part of Letters Patent No. 647,307, daea- April 10, ieoo.

Application filed July 3, 1899- Serial No. 722,622. (No modelJ To all whom it may concern: versation and connected to another circuit Be it known that I, JOHN MORRIS LATIMER, when used for the transmission of the alarm a citizen of the United States of America, and signals. It is important to be independent of a resident of the city and oountyof Philadelthis condition, because when the telephone- 5 phia and State of Pennsylvania, have inventcircuit is connected to another exchange by 55 ed certain new and useful Improvements in means of a trunk connection the telephonea Combined Telephone-Exchange and Firesubscribers clearing-out signal would, ac- Alarm System, of which the following is a cording to usual telephone practice, be out specification. out at the local exchange and only be received The object of this invention is to utilize exin the exchange at the long-distance point in 60 isting telephone-circuits for the transmission the event that the distant subscriber is the of fire-alarm, burglar-alarm, or other signals calling subscriber,and therefore the exchange from a subscribers premises to fire, police, or in which the signal is so received may be in other alarm-receiving headquarters by means another city.

[ of suitable transmitting and repeating appa- In the accompanying three sheets of draw- 65 ratus connected to the telephone-circuit, but ings, which form a part of this specification, so constructed that they will not interfere Figure 1 is a diagram showing the alarm syswith the telephone service or respond to the tem applied to a telephone-exchange system telephone signaling or talking currents. of the magneto type in which the alarm-Sig The invention may be described,briefiy, as nal is sent with current from a source placed 70 the combination of a local alarm apparatus, at the subscribers premises. Fig. 2 shows a subscribers telephone apparatus, a telethe same alarm system applied to a commonphone-circuit which connects the telephone battery telephone-exchange system in which apparatus with a telephone-exchange, which the alarm-signal is sent with current from a 2 5 circuit is utilized for the transmission of sigsource located at the subscribers premises. 75 nals from the local alarm apparatus, a relay Fig. 3 is a diagram showing-the alarm system in the telephone-circuit so utilized, which reapplied to circuits of a common-battery telelay is at the exchange and is constructed so phone-exchange system, the battery at the as to be responsive only to signals transmitted telephone-exchange being the source which from the local alarm apparatus, and an alarmsupplies current for the alarm-signals trans- 8o circuit from the relay to an alarm-receiving mitted from the subscribers premises.

. apparatus at the headquarters. The relay in Reference will first be made to Fig. 1. the telephone-circuit is so constructed that it This shows one complete telephone apparawill not interfere with the ordinary operation tus A, a subscribers local alarm-circuit B,

3 5 of the telephone service and that it will not and apparatus 0, the latter consisting in this 8 be responsive to the signaling or talking curcase of an automatic tire-alarm circuit and rents employed in the telephone service. The apparatus, a telephoneexchange D, a telealarm-signal currents may or may not affect phone-circuit E, extending to the telephonethe telephone signal-receiving devices at the exchange, an alarm-repeating relay F in a switchboard; but if they do it is not necesshunt across the telephone-circuit at the tele- 9o sary that any attention be given to them by phone-exchange, a second repeating-relay G the exchange operators, for the alarm-repeatat the exchange, alarm-transmitting circuits ing relay in the telephonecircuit automatic- H H, extending to the alarm-receiving headally repeats the alarm to the headquarters, quarters, and an alarm-receiving apparatus I.

so that its transmission is independent of any The telephone-circuits of three fire-alarm 5 attention from the exchange operators, tosubscribers are indicated at the exchange; gether with the consequent danger of overbut the subscribers end of but one circuit is sight or delay on their part. The construcshown in the figure. A number of alarm-retion is such that it is also immaterial whether peating relays are shown in connection with or not the telephone-circuit is in use for 0011- the fire-alarm subscribers circuits at the tele- I00 which the relay is placed.

they will send a distinctive signal.

phone-exchange. Each relay is actuated from a subscribers alarm apparatus at the subscribers end of the telephone-circuit in In the repeatingrelay here used a permanent-magnet is placed opposite the poles of the electromagnet to retractitsarmature. Thearmatureis normally held open by the attraction of the permanent magnet, but is attracted when a current of suitable strength and duration traverses the coils of the electromagnet in the proper direction. The adjustment can thus be made more positive and sensitive than it would be if the armature were retracted by weight or spring. The alarm-repeating relays by means of their armatures operate a second repeating-relay in a local circuit at the exchange, which in turn operates the alarm-receiving apparatus at the alarm-receiving headquarters through a suitable circuit.

It at the time the alarm is sent in the telephone-circuit is connected through the exchange to another telephone-circuit which contains an alarm-repeating relay for another subscriber, both relays will respond; but as they will respond simultaneously and they repeat into the same alarm-receiving apparatus no confusion will result and the distinctive character of the signal will indicate its source.

Obviously the alarm-receiving apparatus might be operated directly by the alarm-repeating relay. In order that this relay shall not be responsive to the alternating currents generated by the magneto of the telephone system, a retarding-coil K is placed in the shunt in series with the relay. This retarding-coil also prevents the diversion and loss of any of the talking-current of the telephone system through the shunt and relay, since it prevents the passage of rapidly-alternating currents, though it does not obstruct the passage of the more prolonged pulsations of direct current in the signals made by the alarm apparatus.

In one branch of the telephone-circuit is a loop L, leading to the subscribers alarm apparatus, in which is a normally-closed switch M. This switch is permanently shunted by a non-inductive resistance N, which offers little impedance to talkingcurrents. Consequently bad contact at the switch or its opening in sending in an alarm will not interfere with the use of the circuit for telephone purposes.

The alarm-transmitting apparatus at the subscribers premises has a metallic signaling-wheel O, which carries contact-teeth on its periphery. These close a circuit through a local alarm-battery P, which includes the telephone-circuit between the subscribers telephone and the exchange. The contactteeth are of such number and grouping that Suitable driving mechanism actuated by a weight or otherwise is provided to rotate the signalingwheel. This mechanism is controlled by an electromagnet Q in the local alarm-circuit. This electromagnet is normally energized. Upon the opening of the alarm-circuit through the melting of a fuse b or by opening it at the switch I) by hand or otherwise the electromagnet releases the driving mechanism of the signaling-wheel. The driving mechanism may also be releaseddirectly by hand. The end of a switch M normally rests in a notch in a switch-controlling wheel R of insulating material. This wheel is connected with and revolves with the signaling-wheel. Immediately on the starting of the driving mechanism the switch is thrown to a contact S and connects one side of the local battery of the local alarm-circuit to one of the wires of the subscribers telephone metallic circuit and leaves the non-induction resistance in series with the telephone-subscribers apparatus. In the further revolution of the alarm apparatus the signaling-wheel closes and opens at a contact T a connection from the other side of the building alarm-battery to the other wire of the subscribers metallic circuit. This opening and closing throws the local-battery current onto the telephone-circuit, so as to send a distinctive signal. The high resistance of the non-inductive resistance prevents the local-battery current from passing to any extent through the telephonesubscribers apparatus and diverts the current in the direction of the alarm-repeating relay at the telephone-exchange. The alarmrepeating relay repeats the signal to the alarmgiving apparatus at the headquarters. The signal which is transmitted from each building is different, so that although all are received by the same apparatus the distinctive character will indicate the source of the alarm.

The mechanism is preferably so constructed that when released the signaling-wheel will be revolved a number of times and the signal thereby repeated.

In Fig. 2 a modified form of the invention is shown in connection with a common-battery telephone system. The local alarm-battery is normally grounded and only one of the wires of the telephone-circuitis used in transmitting the alarm-signals. At the telephoneexchange in each telephone-circuit to which the alarm system is applied is a polarized relay F in series with the telephone-exchange annunciator-coils U and call-battery V. The coil of each of these relays is inclosed in an -iron sleeve, which forms a part of the magnetic circuit for the coil and prevents crosstalk, which would otherwise beliable between the circuits of adjoining relays in the eX- change. The armature a of the relay plays between a contact-screw c in the end of the relay-core and a contact-screw d in a projection from the iron sleeve. The end of the relay-core and the end of the iron'sleeve, constituting the pole-pieces of the electromagnet of the relay, have the same polarity induced in them by the permanent magnet 6, but have opposite polarities induced in them by the passage of current through the relay. When there is no current through the relay, the armature rests by gravity against the contact-screw in the sleeve. The connection to the telephone call-battery is such that current from it through the relay increases the attraction of the armature toward the sleeve, and it will consequently not be disturbed by the passage of current from the telephone call-battery. Current from the alarm-battery, however, increases the attraction of the armature toward the core, thereby closing the local fire-alarm circuit in the telephone-exchange. To keep the armature from being afiected by alternating currents which are sent out from the exchange to call subscribers, a secondary coil f is so arranged that current will be induced in it whenever alternating currents are sent over the telephone circuit. Current from this is conducted to an electromagnet g, which attracts the relay-armature against the contact-screw in the iron sleeve and prevents its vibration by alternating currents. The relay and in duction coils are combined on one core, and the relay-coil serves as the primary of the induction-coil. The local-alarm-battery current flows through the circuit oppositely to the current from the telephone call-battery. Consequently when current passes over the telephone-line and through the relay the armature is attracted against the contact-screw in the end of the relay-core. This closes a circuit through the relay G, thereby transmitting a signal. This relay is shunted bya non-inductive resistance N,which passes the pulsatory call-signals of the telephone system and the telephone talking-currents. Hence the alarm-receivin g relay offers no impedance to the telephone service. In the figure the non-inductive resistance is shown outside of the relay; but it may, however, be conveniently wound on the core of the relay.

For convenience of diagrammatic representation separate call-batteries are shown at the exchange for each telephone-circuit; but in practice a single battery or equivalent source of energy supplies all the telephone-circuits, and it may also supply the alarm-circuit to the alarm-receiving apparatus.

Normally the local alarm apparatus is electrically separated from the telephonecircuit, for the wire which leads from that circuit to the signaling-wheel of the building alarm-circuit is normally open at the contact T. When, however, the local alarm-circuit is opened, the relay in that circuit releases the signaling-wheel mechanism and the Wheel commences to revolve, with the result that each time the contact is closed at the teeth on the signaling-wheel a ground-circuit is formed between the subscribers premises and the telephone-exchange and the current from the local alarm-battery reverses the previous polarity of the alarm-repeating polarized relay and its armature is repelled. The polarized alarm-repeating relay may be of any suitable construction.

In Fig. 3 a common-battery exchange sys tem is again represented. In this the telephone-exchange battery is utilized to operate the alarm-repeatin g relay when alarm-signals are transmitted by the local-alarm-circuit apparatus. For this purpose a non-polarized or ordinary relay is used. It is placed in one of the wires of the metallic telephone-circuit and in series with the ordinary telephone apparatus. The armature of this relay is normally withdrawn by its retractile spring, and the adjustment is such that current flowing in the telephonecirc uit will not be sufficient to attract the armature. When alternating currents are sent from the exchange to call a subscriber, they preferably pass through the non-inductive resistance instead of through the relay. W'hen the normal resistance of the telephone-circuit in the subscribers build ing is reduced by any suitable means, the current flowing through the alarm-repeating relay is thereby increased and its armature is attracted. To effect this increase of current, a shunt of lower resistance than the telephonesubscribers apparatus is closed across the telephone-subscribers circuit and between the telephone-subscribers apparatus and the telephone-exchange. This shunt is normally open at the local alarm signaling wheel. When, however, the local alarm-circuit is opened and the signaling-wheel is released, this is alternately closed and opened, with the result that the alarm-receiving relay is closed and opened a number of times and the dis tinctive signal of the subscribers building is transmitted.

The alarm-repeating relay is provided with a non-inductive resistance across its coils, as in the form previously described.

It will be seen that in each form of the invention the alarm-repeating relay is not operated by the currents ordinarily used in the telephone service. In each form shown the local alarm apparatus controls devices which when set in operation complete electrical connection with the telephone-subscribers circuit, and when this has been done alarm-signals are transmitted by said devices over the subscribers telephone-circuit, thereby operating the alarm-repeating relay and through it the alarm-giving or alarm-announcing apparatus. In the arrangement shown in Fig. 1 the alarm-repeating relay is operated by the opening and closing of the local battery through the signaling-wheel. In Fig. 2 the alarm-repeating relay is operated by current from the alarm-transmitting circuit of opposite polarity to the current normally flowing in the telephonecircuit. In Fig. 3 the alarmrepeating relay is operated by reducing the normal resistance of the telephone-circuit, which reduction of resistance is effected by the closing of a shunt-circuit across the terminals of the telephonesubscribers apparatus, whereby the normal amount of current flowing through the alarm-repeating relay is increased and its armature is attracted wit the result specified.

It is not material to the system that the telephone-circuit utilized for the transmission of an alarm should be from a telephone in the same building or premises with the alarm apparatus, for it may be connected to any telephone-circuit any part of which is conveniently near. Also the alarm-receiving apparatus maybe located in the same premises with the alarm-repeating relay.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. The combination of a telephone apparatus, a telephone-exchange, a telephone-circuit connecting the telephone apparatus with the telephone-exchange, a local alarm apparatus connected to the telephone-circuit, between the telephone apparatus and the telephone-exchange, a relay in the telephone-circuit, which relay is at the exchange and is responsive to the currents controlled by the local alarm apparatus and not to the telephone signaling and talking currents, an alarm-receiving apparatus, and an alarm-circuit to the alarm-receiving apparatus which is controlled by the relay, substantially as described.

2. The combination of a telephone apparatus, a telephone-exchange, a telephone-circuit connecting the telephone apparatus with the telephone-exchange, a local alarm apparatus connected to the telephone-circuit, a relay in the telephone-circuit, which relay is at the exchange, and is responsive to the currents controlled by the local alarm apparatus and not to the telephone signaling and talking currents, an alarm-receiving apparatus which is independent of the telephon e-circuit, and is controlled by the relay, substantially as described.

3. The combination of a telephone apparatus, a telephone exchange, a telephone-circuit connecting the telephone apparatus with the telephone-exchange, a local alarm apparatus connected 'to the telephone-circuit between the telephone apparatus and the telephone-exchange, a relay in the telephone-circuit, which relay is at the exchange and is responsive to the currents controlled by the local alarm apparatus and not to the telephone signaling and talking currents, an alarm-receiving apparatus, and an alarm-circuit to the alarm-receiving apparatus which is independent of the telephone-circuit and is controlled by the relay, substantially as described.

4. The combination of telephone apparatuses, a telephone-exchange, telephone-circuits connecting the telephone apparatuses with the telephone-exchange, local alarm apparatuses connected to the telephone-circuits, relays in the telephone-circuits, which relays are at the exchange and are responsive to the currents controlled by the local alarm apparatuses and not to the telephone signaling and talking currents, an alarm-receiving apparatus, and an alarmcircuit tothe alarmreceiving apparatus which is controlled by any of the relays, substantially as described.

5. The combination of telephone apparatuses, a telephone-exchange, telephone-circuits connecting the telephone apparatuses with the telephone-exchange, local distinctive signaling alarm apparatuses connected to the telephone-circuits, relays in the telephone-circuits, which relays are at the exchange and are responsive to the currents controlled by the distinctive signaling alarm apparatuses and not to the telephone signaling and talking currents, an alarm-receiving apparatus, and an alarm-circuit to the alarm-receiving apparatus which is controlled by any of the relays, substantially as described.

6. The combination of a telephone apparatus, a telephone-exchange, a telephone-circuit connecting the telephone apparatus with the telephone-exchange, a localalarm-circuit and local battery therefor, means controlled by the local alarm-circuit for connecting the local battery to the telephone-circuit, a relay in the telephone-circuit, which relay is at the exchange and is responsive to the current from the local battery and not to the telephone signaling and talking currents, and an alarmreceiving apparatus which is controlled by the relay, substantially as described.

7. The combination of telephone apparatuses, a telephone-exchange, telephone-circuits connecting the telephone apparatuses with the telephone-exchange, local alarm-circuits and local batteries therefor, means controlled by the local alarm-circuits for connecting the local batteries to the telephone-circuits, relays in the telephone-circuits, which relays are at the exchange and are responsive to the currents from the local batteries, and not to the telephone signaling and talking currents, and an alarm-receiving apparatus which is controlled by any of the relays, substantially as described.

8. The combination of a telephone apparatus and a telephone-exchange, a telephone signaling-battery therefor, a telephone-circuit connecting the telephone apparatus with the telephone-exchange, a local alarm apparatus and local battery therefor, the local battery and telephone signaling-battery being oppositely connected to the circuit, a polarized relay in the telephone-circuit, which relay is at the exchange and is responsive to the currents from the local battery, and not to the telephone signaling and talking currents, an alarm-receiving apparatus, and an alarm-circuit to the alarm-receiving apparatus which is controlled by the relay, substantially as described.

9. The combination of telephone apparatuses and a telephone-exchange, a telephone signaling-battery therefor, telephone-circuits connecting the telephone apparatuses with the telephone-exchange, local alarm apparatuses and local batteries therefor, the local IIC batteries and the telephone signaling-battery being oppositely connected to the circuits, polarized relays in the telephone-circuits, which relays are at the exchange and are responsive to the currents from the local batteries and not to the telephone signaling and talking currents, an alarm-receiving apparatus, and an alarm-circuit to the alarm-receivin g apparatus which is controlled by any of the relays, substantially as described.

10. The combination of a telephone apparatus, a telephone-exchange, a telephone-circuit connecting the telephone apparatus with the telephone-exchange, a local alarm apparatus connected to the telephone-circuit, a relay in the telephone-circuit, which relay is at the exchange and is responsive to the currents controlled by the local alarm apparatus and not to the telephone talking-currents, an alarm-receiving apparatus, an alarm-circuit to the al arln-receivin g apparatus which is controlled by the relay, a secondary coil, means for inducing current in the secondary coil by current in the telephonecircuit, and an electromagnet, which is connected to the secondary coil for preventing the operation of the alarm-circuit, substantially as described.

Signed by me in the borough of Manhattan, New York city, State of New York, the 30th day of June, 1899.

JOHN MORRIS LATIMER. Witnesses:

THOMAS EWING, Jr., SAMUEL W. BALOH. 

